Adhesive composition



Patented June 2, 1931- UNITED STATES PATENT OFFICE ERNEST norxmson,

OE NEW YORK, N. Y.

ADHESIVE COMPOSITION m Drawing. Original application filed August 18,

cation filed September 28,

tioned are inflammable and expensive. Their expensiveness is due to theloss of the solvent or cost of maintaining solvent recovery apparatus.It is also diificult to manipulate these cements having a high rubbercontent due to their high viscosity. Hence a limit is placed in actualpractice on the rubber content which must be such that the cement may beeasily applied. These rubber cements also penetrate textile andother-surfaces with difficulty and this fact is another objection totheir use. i

It is an object of this invention to provide a rubber cement which cancontain a high percentage of rubber and remain sufficiently fluid to beeasily manipulated. It is a further object to provide a rubber cementcontaining an aqueous dispersion of rubber and having its properties ofviscosity, plasticity,

adhesiveness and cohesiveness modified.

This case is a division of my copending application Serial No. 658,184,1923, now Patent 1,657,472, Jan. 31, '1928.

Latex as such may be used as the adhesive and the following is anexample of such use: Latex containing of solid material and preservedwith 12% of ammonia in accordance with the usual practice, where latextions, is, applied to the ,fiesh side of each of two pieces of leather.The latex is, allowed.

to soak into the leather surfaces and then a second coating is appliedwhich is also allowed to stand until evaporation and absorption haveoccurred sufiicient to leave the surfaces in a damp sticky state. Thesurfaces arethen firmly pressed together and are allowed to stand thusproducing a bond of dry rubber 6 latex joining the two surfacestogether. The

- ordinary,

Rubber filed'A'ugust 18,

is transported to a distance from the planta 1923, Serial No. 658,184;Divided and this applica- 1927. Serial No. 222,689.

bond thus produced when compared with an leather cement procured on theopen market Where both the latex and the cement were applied inapproximately equal quantities in the manner indicated above tested asfollows:

I Stripping Flexing Material test .test 1 Latex (containing 35% solids)1,4 lbs. 6 min. Ordinary leather cement 7%lbs. 2min.

tion until flexed three times as long as the ordinary leather cement.

It is often found desirable instead of employing latex as such to modifyits properties including viscosity, plasticity, adhesiveness,cohesiveness and surface tension, to adapt it to the texture of variousmaterials, particularly so that there amount of penetration andadhesiveness and a firm bond established between the two surfaces. Forinstance the lack of plasticity of latex is apt to cause it to penetratedry or open texture leather too readily, rendering a single coatinefi'ective as a bond and making it likely that where successive coatsare applied the latex will strike through or penetrate to the oppositesurface of the material. This low plasticity is especiallydisadvantageous where the building up of layers of cemented fabrics iscarried on as in combining cloth due to the fact that the latex on theouter surface. The following reprewill be the right sents latex theproperties of which have been altered: Latex equivalent to parts byweight of dry rubber, 20 parts of dextrine, 2 parts of zinc oxide, 2tparts of sulphur, 4 parts of glue, 2. parts 0 oxy normal butyl rivativeof carbon disulphide, emulsified in solvent naphtha as indicated below,2 parts of dibenzylamine also emulsified in solvent naphtha, 2 parts ofSilurian shale. In combining the above substances the followingprocedure is preferably carried out :The sulphur and zinc oxide areadded to the dextrine and Silurian shale as a thick wet paste. Anemulsion of oxy normal butyl thiocarbonic acid disulphide is made bydissolving 5 parts of this material in parts of solvent naphtha, whichmixture is then emulsified with parts of water in the presence of 5parts of .glue. Similarly an emulsion is made of dibenzylamine using thesame relative proportions of solvent na htha, water and glue. Quantitiesof each 0% these emulsions eqiulivalent to 2 parts of the oxy normalbutyl t 'ocarbonic acid disulphide and the dibenzylamine respectivelyare now added to the latex mixture. This composition is a fluid masswhich is applied to the flesh side of each of two sheets of leather andallowed to penetrate. A second coat is then applied if desired andallowed to stand until evaporation and absorption have occurred,whereupon the surfaces are firmly pressed together. Uponstandingavulcanized bond results. Instead of oxy normal butylthiocarbonic acid disulphide and dibenzyl amine, any other suitablederivative of carbon disulphide and any other suitable amine may beused, such as those disclosed in patent to Cadwell 1,440,962.

In the above composition the dextrine, a

' hydrophil colloid serves to modify the viscosity and adhesiveness ofthe latex. It may be replaced in part or entirely by an equivalentamount of glue or other organic hydrophil colloid. Silurian shale actsto modify both the viscosity and plasticity and effects also thecohesiveness of the mass. Instead of Silurian shale, other colloidalclays may be used. Glue increases the viscosity and adhesiveness of the.mass. Zinc oxide increases its plasticity. Glue and zinc oxide bereplaced by other organic colloids other. materials for altering thelasticity of the mass respectively if deslred. Concentrated ordilutelatex'may be used instead of ordinary latex having a normal solidcontent. Tests of leather employing the modified latex compositioncompared with ordinary leather cement show similar improvement to thatgiven above in connection with latex.

The latex composition above described can be employed for example in themanufacture of shoes. Parts of the uppers may be bonded by thecomposition or the upper may be bonded to a sole. Various other uses maybe made of the composition in the manufacture of shoes and other leatherarticles. vIt will .be further understood that the surfaces of variousmaterials other than leather may be united by the composition. Forexample forms of fibrous material either as textile material orotherwise may be joined. The composition may be used to join cotton andcotton, woolen and woolen, fibres or cloth, and similarly between cottonand wool either in the form of fibres or cloth. Similarly lamiuse orgreater thicknesses .of wood may be united. Of course the materialsmentioned and various other materials may be united to leather by thecomposition.

It will be understood that instead of normal latex containing 35%solids, diluted or concentrated latex may be employed it desired.Artificial ber can also be use It will be noted that the adhesivecompositions above recited have in eneral the properties above setforth. T e expensive 111- flammable solvents such as gasoline andsolvent naphtha are generally avoided as well as the use of rubber whichhas been coagulatalueous dispersions of rub-- ed and milled to prepareit for solution, and

from which on account of such operation certain valuable constituentshave been lost.

In general the compositions provided have improved wear-resistant andageing properties. The compositions employed may be easily and quicklymade.

As many apparently widely different embodiments of this invention may bemade without departing from the -spirit thereof,

it will be understood that I do not intend to limit to self'to thespecific embodiment herein emp oyed except as indicated inthe appendedclaims.

Having thus described my invention, what I claim and desire to protectby Letters Patent is:

porous material comprising an aqueous dispersion of rubber, an organiccolloid, a colloidal clay, and a vulcanizing agent.

2. An adhesive composition for bonding porous material comprising anaqueous dispersion of rubber, an organic hydrophil col- 'loid, acolloidal clay, and a vulcanizln combonding porous materialcomprising anI p a ueous dispersion of rubber, an organic col- 101d, a colloidal clayand low temperature vul canizing ingredients.

Signed at New York, New York, 26th I day of September, 1927.

ERNEST HOPKIN SON.

105 1. An adhesive composition for bonding

